Something that seems to annoy newer animators (and myself until recently) are the character meshes clipping inward on themselves during posing or animating. This can be quite annoying and for me at least detracts from the animation.
You can fix this most of the time by moving the thigh bones around AFTER removing the IK rig from the model. Just make sure you are done with animating, as reapplying the IK rig will reset the limbs to the original position (on some models). With a bit of good camera placement, the pose can look natural, even if the character no longer does. This works for hips and knees a lot too.
Hope this helps someone.